Misuse of “Power” and other mechanical terms in sport and exercise science research

In spite of the Système International d’Unitès (SI) that was published in 1960, there continues to be widespread misuse of the terms and nomenclature of mechanics in descriptions of exercise performance. Misuse applies principally to failure to distinguish between mass and weight, velocity and speed, and especially the terms "work" and "power." These terms are incorrectly applied across the spectrum from high-intensity short-duration to long-duration endurance exercise. This review identifies these misapplications and proposes solutions. Solutions include adoption of the term "intensity" in descriptions and categorisations of challenge imposed on an individual as they perform exercise, followed by correct use of SI terms and units appropriate to the specific kind of exercise performed. Such adoption must occur by authors and reviewers of sport and exercise research reports to satisfy the principles and practices of science and for the field to advance

Physiological changes with periodized resistance training in women tennis players

Purpose: To compare the physiological and performance adaptations between periodized and nonperiodized resistance training in women collegiate tennis athletes. Methods: Thirty women (19 ± 1 yr) were assigned to either a periodized resistance training group (P), nonperiodized training group (NV), or a control group (C). Assessments for body composition, anaerobic power, V̇O2max, speed, agility, maximal strength, jump height, tennis-service velocity, and resting serum hormonal concentrations were performed before and after 4, 6, and 9 months of resistance training performed 2-3 d∙wk-1 Results: Nine months of resistance training resulted in significant increases in fat-free mass; anaerobic power; grip strength; jump height; one-repetition maximum (1-RM) leg press, bench press, and shoulder press; serve, forehand, and backhand ball velocities; and resting serum insulin-like growth factor-1, testosterone, and cortisol concentrations. Percent body fat and V̇O2max decreased significantly in the P and NV groups after training. During the first 6 months, periodized resistance training elicited significantly greater increases in 1-RM leg press (9 ± 2 vs 4.5 ± 2%), bench press (22 ± 5 vs 11 ± 8%), and shoulder press (24 ± 7 vs 18 ± 6%) than the NV group. The absolute 1-RM leg press and shoulder press values in the P group were greater than the NV group after 9 months. Periodized resistance training also resulted in significantly greater improvements in jump height (50 ± 9 vs 37 ± 7%) and serve (29 ± 5 vs 16 ± 4%), forehand (22 ± 3 vs 17 ± 3%), and backhand ball velocities (36 ± 4 vs 14 ± 4%) as compared with nonperiodized training after 9 months. Conclusions: These data demonstrated that periodization of resistance training over 9 months was superior for enhancing strength and motor performance in collegiate women tennis players. Reprinted by permission of the publisher